A conventional HID (high intensity discharge) lamp is an arc-type lamp which produces light by forming an electric arc between electrodes housed in a fused alumina arc tube or transparent fused quartz filled with gas and metal salts. To achieve greater energy efficiency, it has been proposed to produce HID lamps that are retrofittable to conventional HID lamp holders but produce light via LEDs (light emitting diodes) instead of via an electric arc.
There have been reports of cases of arcing between an HID lamp base and the lampholder/socket in some field installations. The arcing may develop over time and may result in damage to the lamp. In some instances, the damage to the lamp may also result in a safety hazard.
In a proposed remedial response to the issue of arcing and damage to HID lamps, it has been recommended that high wattage HID lamps be used with mogul base lampholders that have center electrical contacts made of nickel plated copper alloy or stainless steel, with a supplemental coil spring to increase contact pressure and reduce the possibility of arcing. However, the recommended remedial response may be viewed as expensive, and may well not be implemented for a large proportion of existing installed lamp sockets.